This part is a FACTORY ORIGINAL Tier 1 4GB DDR3 1333MHz DR UDIMM memory module (from either Samsung, Micron, Hynix, Infineon, etc.). You cannot buy a better memory upgrade, and there is a good chance that this will be identical to what you may get directly from the OEM. Adding additional memory is the best way to increase the performance of your system. All our memory is built to JEDEC Standards, to meet or exceed the Tier 1 OEM's factory requirements, and 100% guaranteed to be compatible with the systems it is intended for. We guarantee your product will work right the first time. Our products are guaranteed by the MAGNUSON-MOSS WARRANTY ACT to not affect or void OEM warranties.